This invention relates to safety relief valves of the direct spring closing type which automatically closes after being opened.
1. Field of the Invention
Direct spring operated safety relief valves for controlling fluid pressure are known.
2. Description of the Prior Art
The most pertinent patent is believed U.S. Pat. No. 3,411,530 issued Nov. 19, 1968 to Powell for Pressure Operated Pop Valve. This patent discloses a spring-type pressure responsive relief valve which features a valve closing a seat between inlet and outlet ports, and includes a cage surrounding the valve within the valve body has restrictive outlet ports for restricting the flow through the valve when opened by excessive pressure. A port feeds the upstream pressure into the bonnet of the gate valve surrounding the release spring for generating fluid pressure which assists the spring in closing the valve by creating an unbalanced fluid pressure force against the valve to move it to a valve seat closed position.
This invention improves the self closing action of such a valve by providing a pressure chamber adjacent the downstream side of a disk surrounding the valve opposite the seat.